Pre flop I decide to 3bet as a bluff. I have position and will have the iniative with a hand that can flop pretty well in case he calls. Plus I should have decent fold equity against him to begin with.

On the flop I have a pretty mandatory cbet I think. He could have some Ax that he missed, and if he does have a made hand I have plenty of outs to improve.

Additionally, if I don't hit I can probably take it down pretty often on the turn against second pair type hands on a good card.

With that said, I think I should fire another barrel on the turn like I did. He might fold a K, though I highly doubt that. He might also fold a better flush draw since he's out of position, but that's also a long shot probably. However, he will almost certainly fold all his pairs QQ-99 or random 8x that he might have called with (98s/87s mostly).

That said, would it be better to check behind the turn to see a free river card and not bloat the pot too much with a bluff in a 3bet pot? Or is betting to try and take it down better.

As played, I didn't see much reason to barrel again. If he has a K he is of course never folding, and I only fold out the couple of better flush draws he might have, which probably aren't too many combos.